If people who consumed the raw milk become ill, they should consult a physician

Consumers who purchased raw milk from the Swiss Villa Dairy Farm in Lykens, Dauphin County, at any time after Feb. 9 are advised to discard it immediately due to the risk of Listeria monocytogenes contamination, Agriculture Secretary Dennis Wolff said today.

Raw milk has not been pasteurized or homogenized.

No illnesses have been reported as a result of the potential contamination, but if people who consumed the raw milk become ill, they should consult a physician.

"During routine testing, samples taken at the dairy tested positive for Listeria monocytogenes," said Wolff. "If consumers have raw milk from this farm, they should discard it immediately as a precaution."

Samples were taken from the farm on Feb. 9 that tested positive for Listeria monocytogenes on Feb. 16. Until multiple laboratory samples test negative, the Department of Agriculture recommends against drinking unpasteurized milk from the farm. The farm's milk can continue to be safely sold for pasteurization to a processing facility.

The owner of the farm is cooperating with the department to identify and resolve the contamination source.

Symptoms of Listeriosis are fever, muscle aches, and sometimes gastrointestinal symptoms such as nausea or diarrhea. If infection spreads to the nervous system, symptoms such as headache, stiff neck, confusion, loss of balance or convulsions can occur.

Infected pregnant women may experience only a mild, flu-like illness, but infections during pregnancy can lead to miscarriage or stillbirth.

Symptoms of Listeriosis can appear in four days to three weeks.

Pennsylvania farms selling raw milk must be permitted and have samples of their milk laboratory tested due to the potential health risks associated with the unpasteurized products.